A great variety of pathogenic microorganisms such as bacteria and fungi are causative agents in producing diseases in man, animals and plants. Although a number of antibiotics have been developed, some of which possess usefully high antimicrobial activity against one or more pathogenic microorganisms, there remains a need for more effective agents to combat the many diseases caused by these microorganisms in man, animals and plants.
An object of this invention is to provide new antibiotics which are useful as antibacterial agents for therapeutic treatment of bacterial infections in man and animals and/or for sterilization of surgical materials and instruments. A further object of this invention is to provide processes for the production of these new antibiotics. Other objects of this invention will be clear from the following description.
We have made extensive research in an attempt to produce new and useful antibiotics. As a result, we have now found that when a new strain of the genus Streptomyces which was isolated from a soil sample collected in Tada-u-mi-cho, Takehara City, Hiroshima Prefecture, Japan, is cultivated in a culture medium under aerobic conditions, a substance exhibiting antibacterial activity against gram-negative and gram-positive bacteria is produced and accumulated in the culture. We have now succeeded in isolating this antibacterial substance from the culture and purifying it. As result of studies of the chemical, physical and microbiological properties of this isolated substance, it has been confirmed that this substance is a new antibiotic which is distinguishable from any of the known antibiotics. Thus, we have designated this new antibiotic as SF-1771 substance.